Is there a trick to the Condor Wheel Stop?

[Scrubs]

I have been using a Condor Pit-Stop/Trailer-Stop model PS-1500 for about two years now.

I like it because it works great, in and out of the trailer, as advertised for $250.

But works best when secured it's to the floor, or on rough pavement like my driveway.
Anytime I use it on my painted garage floor, the 21 x 3.5 inch front wheel/tire on my Night Train will not rock out of the cradle.
Instead, the whole assembly (and the bike) just keep scooting backwards and I have to have someone hold the Condor while I sit astride the bike and pull it out of the Condor unit.

When I'm working alone it gets a bit dicey.

Any help is appreciated.

[Ahar]

velcro

or I also used a non skid rubber mat (linemans blanket)
like all things fun, you need more friction.

[Glenn W]

Couple ways to go about this, including the friction mentioed above. Another thought is to possibly adjust the pivot point when using the stand indoors to hold the bike compared to how you'd have it to trailer. The more the bike ges "up & over" the rocking wheel holder, to more secure but harder to back out it will be. If you move the rocker pivot forward so the axle barely goes past the pivot point it'll be less stable but easier to back out. Once in place use the velcroed strap it came with and it'll be plenty solid for normal cleaning and such.
Another thought is to drill 2 1/4" or so holes in your garage floor where it normally resides and drop bolts in as pins to keep the dock from sliding. They'd only have to be an inch or two deep and a masonary bit is cheap.